Magformers Smart Set- Found these guys at $149.99. That's a crazy good deal. Not only are you getting them at $1 a piece but you are also getting pieces that pretty much NEVER come in the same set. If your child is only 6 and you don't want to overwhelm, I suggest you buy it, give him only 1/3 of the set and keep adding as he/she gets older.

Honestly, I am doing everything in my power not to push the button on this one.

UPDATE: 12/6/13

I guess my power just ain't strong enough. I caved. But I was so surprised! This box is HUGE!

found these guys at $25.00. That's a crazy good deal. At that price, I would even try buying three. I don't really care to have tons of different colored pieces anyway. You can see the structure better with just one or two colors.

I think any building-savvy 6 or 7 year old is going to need two of these boxes.